Study Of Digital Speckle Correlation Matching Method Of Binocular Vision Measuring

With the rapid development of manufacturing, the measurement research of3Ddeformation and surface profile for various loaded materials and structure plays a significant rolein the fields of material test, quality control, reverse engineering, and so on. Vision measurementgets more recognition and investigation for its quality of non-contact, integration and stability inrecent years. Digital image correlation method has advantages of non-contact and high precision,and an image measurement technique by applying computer vision, which has been used inexperimental mechanics, various engineerings and other research fields. so in this paper, thepractical and effective measurement method is applied to surface deformation measurements.As for the problem of surface deformation measurements, a digital method on speckle wasused to apply on matching images corresponding points, combined with binocular visionmeasurement system, which was applied to the deformation of the sheet surface measure-ments.This paper studied the relevant contents of the following four aspects:First of all, based on the camera imaging model, the model of binocular vision measure-ment system and epipolar geometric relationship were analyzed and inferred the calibrationprocesses of internal, structure and position of around camera, then by the means of evaluationparameters of calibration experiments demarcated the accuracy. Secondly, using themathematical model of digital speckle correlation method analyzed the specific solution ofseveral commonly sub-pixel search methods. Using Gaussian function as light intensitydistribution function generated computer simulation speckle images, and the calculationprecision when simulation speckle images were parallel translation was compared with thesub-pixel algorithms. Then, considering the actual gray value changes caused by environmentalfactors in the imaging process, the digital speckle correlation method based on nonlinear graychange model was proposed, and using the computer simulation speckle images and the actualspeckle image in experiments compared the gray change sensitivity and precision and efficiencyof speckle matching in three kinds of gray models. Finally, the actual sheet surface deformationmeasurement experiments were proceeded to test the feasibility and accuracy of surface deformation measurement methods in this article.In this paper, the research work has a certain practical significance for achievingnon-contact measurement surface deformation.